On Aug. 23, a headless female torso attached to a piece of metal to make it sink, washed ashore in Copenhagen. Police identified it as Wall's and said blood inside the submarine matched DNA samples retrieved from her hairbrush.

The cause of her death has not been determined, although prosecutor Jakob Buch-Jepsen told a court on Monday that Wall was stabbed at least 15 times in the rib cage and genitals.

Videos were also recovered on Madsen's computer showing women being strangled, decapitated and burned. He claimed the computer hard drive were not his, saying it was accessible to other people in his laboratory.

The head and legs of Swedish journalist Kim Wall have been recovered six weeks after her torso washed ashore in Copenhagen (Mogens Flindt/AP)

Wall, 30, was a freelance journalist from Sweden who attended Columbia Journalism School in New York, and reported on stories from Sri Lanka to North Korea.